Mist Elimination Liquid-Liquid Coalescing

Mist Elimination Equipment for gas-liquid separations and vapor flow conditioning. In any process where gas and liquid come into contact, the gas will entrain some amount of the liquid droplets. This entrainment can cause process inefficiencies, product loss, and equipment damage. Droplet Formation The way that droplets are formed determines the size of droplets to be removed. Knowledge of the mechanisms that cause droplet formation and the resulting droplet size is essential to proper mist eliminator selection and design. Entrainment can be generated by the following mechanisms: Mechanical action...

Common Applications Knockout Drums Distillation Towers Designing knockout drums to include mist eliminators will reduce capital equipment costs and improve efficiency. Knockout drums relying solely on gravity settling remove only drops larger than 100 microns. Using an efficient mist eliminator will prevent entrainment of all drops larger than 5 to 10 microns. This higher efficiency reduces product loss; downstream corrosion; contamination; and damage to equipment such as compressors, molecular sieve driers, and blowers. Vessel weights can easily be reduced to half, and handling of liquid slugs...

Process Applications Refineries Mist eliminators in fractionators increase throughput capacity and allow deeper cuts for greater yields. Designers and operators of gas absorption systems use glycols, amines, and other proprietary solvents to remove water vapor, H2S, CO2, or other contaminants from gas streams. However, they often follow equipment specifications that have not been optimized to minimize losses of these expensive chemicals. Losses can result from several causes, including the following: In atmospheric and vacuum pipestills, reduced entrainment from the wash oil zones allows deeper...

Equipment Selection Guide Products are available in a wide range of metals, plastics, thermoplastics, and fiber-reinforced plastics for a wide range of applications, such as absorber towers, scrubbers, knockout drums, evaporators, pollution control, and general mist elimination. While the suggestions on this page provide a starting point for the selection of a mist eliminator, your nal choice should be made only after reviewing your application with an equipment designer of proven expertise. Koch-Glitsch provides expert resources to help you make the best choice for your particular application....

DEMISTER™ Mist Eliminators High collection efficiency and low pressure drop. The DEMISTER™ mist eliminator is an assembly of YORKMESH™ knitted mesh that is supported with high open area grids. DEMISTER mist eliminators are made to any size and shape from a wide range of materials, both metal and non-metal. Stainless steels and exotic alloys are fully annealed to provide maximum corrosion resistance. Based on years of actual in-plant performance, Koch-Glitsch engineers use special families of mesh styles for particular equipment and processes to meet customer efficiency requirements. Characteristics...

Design Parameters High Capacity DEMISTER™ Mist Eliminators For general design, Equation 1 has been used as a velocity guideline for many years. Koch-Glitsch has developed and rened a new family of DEMISTER mist eliminators that replace traditional knitted mesh styles. V = K [(oL – ov) / ov]½ Table 2. Units for Equation 1 ft/sec m/sec ρv - vapor density K - capacity factor The new high capacity styles take advantage of improved knowledge about the way internal wire geometry affects capacity and performance in the same way that structured packing surpassed random packing performance in distillation...

FLEXICHEVRON™ Mist Eliminators Lowest pressure drop and high liquid loads. FLEXICHEVRON™ mist eliminators are baffle or zigzag blade modules tailored for either vertical or horizontal flow installations. Depending on design parameters and operating conditions, these mist eliminators collect essentially 100% of all particles greater than 8 to 40 microns in diameter. Manufactured in virtually any size from a wide range of metal alloys, thermal-set plastics, and fiber-reinforced plastic (FRP), over 20 different styles can be designed and fabricated. Applications for which FLEXICHEVRON mist eliminators...

Design Parameters The reentrainment point is a function of gas velocity, as well as other physical properties, e.g., vapor density, liquid density, and liquid surface tension. The reentrainment point is also highly sensitive to the geometry of the chevron. A chevron with superior liquid draining capability and optimum chevron blade spacing can be operated at a higher reentrainment point, yielding a higher capacity. The difference between droplet penetration and reentrainment is often confused. Droplets that penetrate the chevron are too small to be effectively removed by impaction. On the other...

High Capacity FLEXICHEVRON™ Mist Eliminators Special designs for higher pressure systems. The higher capacity FLEXICHEVRON™ style 250 and 350 mist eliminators rely primarily on separate liquid drainage channels for their high capacity. These designs offer higher allowable velocities and different vane geometries. This results in more efficient mist removal, especially at higher pressures where the allowable velocity decreases with the increasing gas density. The unique characteristic of the style 250 or 350 designs is their “double pocket” construction. Strategically located slots allow coalesced...

Performance of High Capacity FLEXICHEVRON™ Mist Eliminators in Air/Water System General Design Parameters Using double pocket FLEXICHEVRON mist eliminators, it is possible to efficiently remove droplets smaller than 10 microns in diameter in clean service even at higher pressures. The table and graph below show the capacity and pressure drop performance of typical designs in an air/water system. Droplet size separation efficiency will be affected by physical properties of the gas and liquid phases, gas velocity, liquid and gas densities, and liquid surface tension. As with other types of mist...